Search found 17 matches

by William Thompson
Tue Dec 27, 2016 6:01 am
Forum: OpenSim
Topic: Turn off text to screen during API calls to Inverse Dynamics
Replies: 3
Views: 247

Re: Turn off text to screen during API calls to Inverse Dynamics

Thanks, Tom, evalc() works, but I am not seeing much improvement in speed in my optimizer code. So i will look for other ways to speed things up.
by William Thompson
Mon Dec 26, 2016 7:53 am
Forum: OpenSim
Topic: Turn off text to screen during API calls to Inverse Dynamics
Replies: 3
Views: 247

Turn off text to screen during API calls to Inverse Dynamics

I am trying to suppress all text output to the screen when running ID from the Matlab API. I have tried using the getVerboseLevel/setVerboseLevel methods as in the following code, but it does not work. Can anyone help identify what I might be doing wrong? --Thanks, Bill %API calls to run ID from Mat...
by William Thompson
Fri Nov 04, 2016 12:08 pm
Forum: OpenSim
Topic: Origin for ground reaction torques in Gait2354
Replies: 4
Views: 468

Re: Origin for ground reaction torques in Gait2354

Here is what is still confusing. The torque about z axis, ground_torque_z, does not appear to be the vertical force, ground_force_vy, times the distance from the origin on the x axis, ground_force_px, while the feet are making contact with the ground. If everything is in global coordinates, I would ...
by William Thompson
Thu Nov 03, 2016 5:52 am
Forum: OpenSim
Topic: Origin for ground reaction torques in Gait2354
Replies: 4
Views: 468

Origin for ground reaction torques in Gait2354

I am trying to understand the ground reaction torques in the provided Gait 2354 example. About what axes are the ground reaction torques contained in the file "subject01_walk1_grf.mot" applied? The documentation at http://simtk-confluence.stanford.edu:8080/display/OpenSim/Motion+%28.mot%29+Files sta...
by William Thompson
Mon Jun 27, 2016 2:34 pm
Forum: Probabilistic Tool for Considering Patient Populations & Model Uncertainty
Topic: ProbGUI_v8?
Replies: 0
Views: 99

ProbGUI_v8?

The tutorial calls for the use of ProbGUI_v8.m, but the download is ProbGUI_v1.m. Is v8 available?

Best,

Bill
by William Thompson
Mon May 16, 2016 6:35 am
Forum: OpenSim
Topic: SO tradeoff for heavy resistance training - stonger muscles or allow higher activation
Replies: 4
Views: 251

Re: SO tradeoff for heavy resistance training - stonger muscles or allow higher activation

i hesitate to modify the model itself by altering the passive force-length curve, because how do you know what to change it to, and what are the unintended consequences of doing that?
by William Thompson
Mon May 16, 2016 6:23 am
Forum: OpenSim
Topic: SO tradeoff for heavy resistance training - stonger muscles or allow higher activation
Replies: 4
Views: 251

Re: SO tradeoff for heavy resistance training - stonger muscles or allow higher activation

Thanks, Colin, the reason you cite is why I am leaning toward expanding the activation range for the muscles to allow them to generate higher active forces. But I am still wondering if that approach has pitfalls, too.
by William Thompson
Fri May 13, 2016 9:06 am
Forum: OpenSim
Topic: SO tradeoff for heavy resistance training - stonger muscles or allow higher activation
Replies: 4
Views: 251

SO tradeoff for heavy resistance training - stonger muscles or allow higher activation

I am using versions of the Arnold lower body model (with mods) and also the new model from Apoorva. In order to make the model strong enough to execute loaded single-leg squats in static optimization runs, it becomes necessary to either increase the Max Isometric strength of the muscles in the model...
by William Thompson
Mon Nov 10, 2014 8:23 am
Forum: OpenSim
Topic: Adjustment of Muscle Parameters
Replies: 9
Views: 2186

Re: Adjustment of Muscle Parameters

Ton, We are using Edith Arnold's model, modified to include the Millard muscle model rather than the older Thelen model. Her model includes multiple wrapping surfaces to accommodate higher degrees of knee flexion that she encountered during running at full sprint. The gait 2392 model you refer to de...
by William Thompson
Thu Nov 06, 2014 11:42 am
Forum: OpenSim
Topic: Adjustment of Muscle Parameters
Replies: 9
Views: 2186

Re: Adjustment of Muscle Parameters

Thanks, Ton, We are seeing fairly good results for heel raise with muscle physiology unchecked and the control range expanded from [0, 1] to [0, 10]. This way the muscles can activate to whatever level is necessary to accomplish the task. Squat results are less satisfying. We are trying to reduce th...